MATH
posted by Kelvin .
Coach Johnson is 10 years older than Tim. When Tim started football 3 years ago, Coach Johnson was twice his age. How old is Tim now?

Tim's current age  x
coach's current age  x+10
3 yrs ago, Tim was x3
3 yrs ago, coach was x+7
(x+7) = 2(x3)
x+7 = 2x  6
13 = x
Tim is now 13
check: if Tim is 13, then coach is 23
3 years ago, Tim was 10 , coach was 20
Yes, he was twice as old then! 
Tim would be 13 years old now coach johnson is 23 now